Predicting Pulmonary Graft Loss Using Oxygen-enhanced MRI T1 Mapping in a Prospective Study

Purpose To investigate the predictive efficacy of oxygen-enhanced MRI T1 mapping parameters for detecting chronic lung allograft dysfunction (CLAD)-related graft loss at 6-12 months and for an additional 2.5 years following pulmonary transplant over a 5.6-year observational interval. Materials and Methods In this single-center, longitudinal, and prospective study conducted between August 2013 and December 2018, parameters from oxygen-enhanced MRI T1 mapping (including oxygen transfer function [OTF], delta T1 oxygenated volume [OV]) were acquired from 141 clinically stable double-lung transplant recipients (6-12 months after transplant) and follow-up (2.5 years after baseline MRI). Applying Kaplan-Meier survival analysis and Cox proportional hazards model, all biomarkers were compared regarding the time to CLAD-related graft loss as the primary outcome measure. Results Participants (n = 141; mean age, 50 years ± 13 [SD], 76 men, 65 women) underwent baseline MRI, of which 132 were analyzed. Over the following 5.6-year observational period, 24 (18%) participants experienced graft loss related to CLAD. At baseline, oxygen-enhanced MRI parameters predicted graft loss within 5.6 years: delta T1 median (hazard ratio [HR], 3.50; 95% CI: 1.0, 9.4; P = .048), quartile coefficient of dispersion (HR, 3.43; 95% CI: 1.1, 8.7; P = .03), and delta T1 oxygenated volume (HR, 3.07; 95% CI 1.18, 7.22; P = .02), while OTF (P = .18) and spirometry (P = .32) did not. At follow-up (91 stable vs 11 graft loss), all parameter changes (follow-up/baseline value × 100 [%baseline]) predicted poorer survival: OTF (HR, 11.1; 95% CI: 2.5, 75.9; P = .001), delta T1 OV (HR, 6.47; 95% CI: 1.52, 27.53; P = .01), and forced expiratory volume in 1 second from spirometry (HR, 7.94; 95% CI: 2.16, 27.4; P = .003). Conclusion Oxygen-enhanced MRI parameters predict CLAD-related graft loss at 6-12 months following lung transplant and 2.5 years after baseline MRI. Delta T1 OV was the most consistent predictor of future graft loss. Keywords: MRI, Lung, Transplantation Supplemental material is available for this article. © RSNA, 2025.